The present invention is directed to a drill bit formed of a first or insertion end part and a second carrier part equipped with drilling cutter members, both parts are joined together by a threaded connection with cooperating stop faces disposed on both parts.
Drill bits having a carrier part equipped with drilling cutter members disposed at an angular endface are used for drilling large boreholes in masonry, concrete or rock. When drilling a borehole a core remains which must be subsequently broken off with a suitable tool.
A drill bit disclosed in DE-GM 18 97 841 is composed of an insertion end part and a carrier part equipped with drilling cutter members where the insertion end part and the carrier part are joined together by a threaded connection.
When marketing the above mentioned known drill bits, the carrier parts having different diameters and different insertion end parts are, for logistical reasons, stocked separately, and the carrier parts and the insertion end parts have uniform connecting regions. Accordingly, within the range of a permissible combination, a carrier part desired by customer can be combined with an insertion end part also desired by the customer. Since the cylindrical connection of the drill bits are detachable, there is a possibility that a person not accustomed to taking the drill bit apart, may screw it into the insertion end of a different carrier part. If the combination of the insertion end part and carrier part effected by a person not skilled in the use of the drill bit is not within the limits of the permissible combinations, there is the possibility that an insufficient drill feed may take place or damage to the drill bit or the driving apparatus may occur.